Jar mechanism



Aug. 17, 1965 R. M. woMAcK JAR MECHANISM Filed Nov. 6, 1963 /K v, E mm .W w 7 WW A /f e m w R United States Patent Oflice lateiated Aug. 'E27, 1935 fitl's .TAR MECHANTSM Robert M. Womach, ilafayette, La., assignor to Drilling j Jars, ifnc., Lafayette, La., a Corporation of Lonisiana Fiied Nov. 6, 1963, Ser. No. 321,895 4 Clairns. (Cl. 175-29) and through vvhich fiuid may circulate through the string i at all times during the operation of the mechanism.

Another object of the invention is to provide jarring mechanism for connection into a string of pipe for rotation therewith in a well bore and which is easily operated to deliver either an upward or a downward impact on the string.

A further object of the invention is the provision of jar mechanism having an outer barrel and an inner mandrel which are telescopingly arranged for relative longitudinal sliding movement and wherein the annular space provided between the barrel and mandrel is filled with oil or other liquid to prevent the entrance of mud or foreign matter between the parts when the mechanism is in use.

Another object of the invention is to provide jarring mechanism which is of simple design and rugged construction, capable of withstanding` the extreme conditions of hard usage to which equipment of this type is customarily subjected.

The above and other important objects and advantages of the invention Will be apparent from the folfowing detailed description, constituting a specification of the same, when considered in conjunction with the annexed drawings, wherein:

FIGURE 1 is a fragmentary, central, longitudinal, crosssectional view illustrating the jar mechanism of the invention and showing the parts in extended position at the time of the delivery of an upward impact with the jar;

FIGURE 2 is a cross-sectional view, on an enlarged scale, taken along the line 2-2 of FIGURE 1, looking in the direction of the arrows; and

FIGURE 3 is a fragmentary, central, longitudinal, crosssectional view, similar to that of FIGURE 1, illustrating a somewhat modified form of the invention.

Referring now to the drawings in greater detail, the jarring mechanism of the invention comprises inner and outer, telescopingly arranged tubular parts Titi and 12, respectively, of which the outer part is a barrel, while the inner part forms a mandrel. The inner part li) is formed at its outer end with an externally enlarged portion 14 which is suitably threaded, not shown, for attachment to the lower end of an upper section of a tubular drilling string or other well pipe, while the outer part or barrel is provided at its lower end with a threaded portion, not shown, for connection to the upper end of a lower section of such drilling string. The threaded end portions of the mandrel and barrel may conveniently take the form of the usual internaily threaded box, not shown, on the mandrel and an externally threaded pin, not shown, on the barrel.

The externally enlarged portion 14 of themandrel and the barrel 12 will usually be of the same external diameter as the sections of the drilling string. The mandrel I 16 is slidably extended into the barrel 12 through the upper end therec-f, and within the barrel the mandrel has an externally enlarged portion 16, mediate its ends, forming a piston in the barrel, which may be provided with external annular grooves for the reception of suitable sealing means, such as O rings 18, to form a fluid tight seal between the barrel and mandrel. At its upper end the barrel has a bushing tl, threada'oly connected thereto, and whose upper end forms an impact face 22, positioned for engagement with an impact face 24 formed on the lower end of the upper end portion 14 of the mandrel, and whose lower end forms an impact face 2'6, within the barrel, against which the upper end of the piston 16 may deliver an impact.

Above and below the piston 16 the mandrel 10 is of somewhat reduced external diameter, smaller than the internal diameter of the barrel 12, to form an internal Chamber 23 in the barrel, which may be filled with a suitable liquid, such as oil, to lubricate the parts and to exclude drilling mud or other foreign matters from the Chamber.

The barrel T2, is provided mediate its ends, beneath the Vpiston ilo of the mandrel, with an internal sleeve-like element 32, which may be formed in two parts, suitably attached to the barrel, as by means of Welding, as indicated at 34. The element 32 may be formed in two separate parts, whose longitudinal side edges are spaced apart to form longitudinal slots in which external projections 36, formed on the mandrel may move. Each of the parts of the sleeve-iike element 32 are formed with longitudinally spaced recesses or notches 38 positioned `to receive peripherally extending, longitudinally spaced teeth itl, formed on the lugs 3d of the mandrel, upon rotation of the mandrel to the left, or counterclockwise, looking downwardly from above, to hold the mandrel and barrel against relative longitudinal movement, the teeth 49 being disengageable from the notches 38 by rotation of the mandrel to the right, or clockwise, looking down from above, to position the lugs 36 in the longitudinal slots between the parts of the sleeve-like element 32, to allow the mandrel and barrel to move longitudinally relative to each other.

The lugs 36 have continuous edge portions 42, extend-` ing longitudinally from end to end of the lugs, opposite the edges in which the teeth il are formed, which edge portions 4% are engageable with adjacent edge portions of the parts of the element 32 to cause the barrel and mandrel to rotate together upon rotation of the mandrel to the right, or clockwise, as viewed from above, when the teeth 4h are disengaged from the notches 33.

The mandrel 19 has a lower end extension 4rd, threadably connected thereto, which carries at its lower end an external annular ring 46, threadably attached thereto and which is formed with cutaway portions 43 in its outer periphery, through which fluid in the barrel may fiow into and out of the lower end of the Chamber 2.3, and within the Chamber, surroundmg the extension 44, above the ring do an annular piston Gil is slidably disposed on the mandrel, which piston is provided with internal and external seal forming means to form a iiuid tight seal between the mandrel and barrel.

The Chamber 2.3 is filled with liquid about the floating piston, and in the event that any of the fiuid in the chamber should escape the ioating piston 5h may rnove inwardly to prevent the entrapment of air or the entrance of foreign matter into the Chamber. The barrel 12 may be provided with a suitable opening 52, into the cham'oer 28, which may be closed by a screw-threaded plug, or the like, and through which the Chamber may he filled with liquid.

The barrel 12 may be formed with upper and lower Sections which are threadably connected together as indicated 'at 54 to facilitate the assembling of the jar.

The parts of the internal sleeve-like element 32 are of sufiicient length, and provided with a sufficient number of recesses 3'8, so that all of the teeth Kttl of the lugs 46' will be positioned in some of the recesses of the element when the mandrel is at either of the extremes of its longitudinal movement in the barrel.

In making use of the jarring mechanism of the invention, the mandrel is connected at its upper end to the lower end of the upper end of 'a drilling string and the lower end of the barrel 12 is connected to the upper end of the lower end of the string, to permit the circulation of drilling fluid through the stem during the drilling operation. With the jar thus connected into the string the string is lowered in the well bore and rotated therein, the edge portions 42 of the lugs 36 being in engagement with the adjacent edges of the parts of the internal sleeve element 32 to cause the barrel to rotate With the mandrel during the drilling operationt In the event that the drill string should become stuck, or that it should be desired for some other reason, to perform a jarring operation on the string, the mandrel may be lowered in the barrel, until the impact face 24 of the external enlargernent 14 of the mandrel engages the impact face 22 of the bushing Ztl, Whereupon the teeth 44D of vthe projections 36 will be in position to enter the lowermost four of the recesses 23 of each of the parts of the internal sleeve element 52, so that upon counterclockwise rotation of the mandrel the teeth Will enter the recesses to lock the mandrel and barrel relative to longitudinal movement. With the parts thus locked against relative longitudinal movement, an upward pull may then be exerted on the mandrel, and the mandrel may then be rotated clockwise to cause the teeth 43 to disengage from the recesses 38, whereupon the mandrel will move upwardly suddenly in the barrel to engage the upper end of the piston ll With the impact face Ze of the bushing 2G, to deliver an up- Ward impact to the string.

Should it be desired to deliver a downward impact to the string, the mandrel may be moved upwardly to engage the upper end of the piston 16 with the impact face 25 of the bushing 20, to position the teeth 45) to enter the three uppermost notches 355 of each of the parts of the internal sleeve element 32, whereupon the mandrel may be rotated counterclockwise to move the teeth lit) into the recesses to lock the parts against relative longitudinal movement. With the parts thus locked a downward force may be eXerted on the mandrel and the mandrel then rotated clockwise to disengage the teeth 49 from the recesses 38, Whereupon the mandrel Will move downwardly suddenly to engage the impact face 24 of the enlargement 14 with the impact face 22 of the bushing Ztl, to deliver a downward impact to the string.

It will be apparent that due to the proportioning of the parts the parts will be automatically positioned to be locked together by counterclockwise rotation of the mandrel when the mandrel is in its uppermost position and also to be locked together by such rotation of the mandrel When the mandrel is in its lowermost position in the barrel, thus facilitating the operation of the mechanism, since it is only necessary to exert an upward pull on the mandrel and rotate the same counterclockwise to assure locking up of the parts, after which a downward jarring action may be exerted by eXerting a downward force on the mandrel and rotating the same clockwise to release the parts, while an upward jarrng action may be accornplished by exerting a downward force on the mandrel to move the mandrel downwardly whereupon the mandrel may be rotated counterclockwise to lock the parts after which an upward pull may be exerted on the mandrel `and the mandrel then rotated clockwise to release the parts.

A somewhat modified form of the invention is illustrated in FIGURE 3 wherein one of the projections 36 of the mandrel is formed with a downwardly extending protection 60, which is slotted longitudinally along one edge to receive one end 62 of a coil spring 54, preferably formed of spirally wound flat strip material, the other end of the spring being formed with an annular ring shaped secured thereto, as by means of screws od, extending through internally threaded openings in the barrel and threaded into corresponding internally threaded openings in the ring, to hold the ring against rotation or longitudinal movement in the barrel. The end 62 of the spring od is slid'able in the longitudinal groove of the extension of), to perrnit the mandrel to move longitudinally relative to the spring, and the spring co-acts with the barrel and mandrel to yieldingly urge the mandrel toward a position of rotation in which the teeth 4d will be in engagement in the recesses 38 of the parts of the internal sleeve-like element 32.

The operation of this form of the jarring mechanismis similar to that described above in connection with the form of the invention illustrated in FIGURE l, the mandrel being rotatively urged toward looking position, so that the parts will be automatically locked together when the mandrel -reaches either of its extreme positions of longitudinal movement in the barrel preparatory to the exertion of a clockwise rotative force on the mandrel to unlock the parts against the resistance of the spring od.

It will also he noted that the spacing apart of the recesses 38 of the parts of the internal sleeve element 32 and of the teeth lit) of the projections e is such that the teeth 40 cannot enter the recesses in any intermediate location of the mandrel in the barrel between the extreme positions of the mandrel therein, thus assuring that the mandrel and barrel cannot be locked against longitudinal movement except when the mandrel is in its uppermost or in its lowermost position in the barrel. Thus, the mandrel may move longitudinally freely in the barrel between its extreme positions When the parts are unlocked from each other, and there is no d'anger of the teeth 4-9 becoming accidentally reengaged in the recesses 38 during a jarring movement of the parts. Moreover, the jarring mechanism may be used to rotate the drilling string either clockwise or counterclockwise in any relative positions of the barrel and mandrel.

It will thus be seen that the invention, constructed and operated as described above provides jarring mechanism which is economically constructed and which is easily and efectively operated.

The invention is dislosed herein in connection with certain specific embodiments of the same, but it will be understood that these are intended by way of example only, and that various modifioations can be made in the construction and arrangement of the parts, within the spirit of the invention and the scope of the appended claims.

Having thus clearly shown and described the invention, what is claimed as new and desired to secure by Letters Patent, is:

ll. In a well jar, inner and outer concentrically arranged tubular parts ro'tatably and longitudinally movable relative to each other, means on the parts forming impact faces positioned for engagement to deliver an impact from one to the other of the parts when the parts reach the limit of their relative longitudinal movement in either direction, interengageable means on the parts positioned for interengagement upon relative rotation of the parts in one direction when the parts are at the limit of their relative longitudinal movernent in either direction to hold the parts against relative longitudinal movement and to be disengaged upon relative rotation of the parts in the other direction to allow such relative longitudinal movement, and means on the parts positioned for coaction to prevent interengagement of said interengageable means When the parts are in positions between the limits of their relative longitudinal movement.

Z. In a well jar, inner and outer concentrically arranged tubular parts rotatably and longitudinally movable relative to each other, means on the parts forrning impact faces positioned for engagement to deliver an impact from one to the other of the parts when the parts reach the limit of their relative longitudinal movement in either direction, interengagaable means on the parts positioned for interengagement upon relativc rotation of the parts in one direction When the parts are at the limit of their relative ion-gitudinal niovement in either direction to hold the parts against relative longituciinal movernent to he diser'gaged upon relative rotation of the parts in the other direction to allow such relative longitudinal movernent, means on said interengageahle means positioned for coactio'n to cause the parts to rotate togetter in said one direction When said interengageable means are interengaged, means on the parts positioned for coaction to cause the parts to rotate together in the other irection when said interengageable means are disengaged and yieldahle means positio-ned for coa-:tion With the parts to yieidingly nrge the parts in said one direction of relative rotation.

3. In a Well jar, inner and outer concentrically arranged tnbular parts rotatahly and longitudinally movahie relative to each other, means on the parts forining impact aces positioned for engagement to deliver an impact from one to the other of the parts when the parts reach the limit of their relative longitudinal movement in either direction, interengageahle means on the parts positioned for interengagernent upon reiative rotation of the parts in one direction When the parts are at the limit of their relative longitndinal movement in either direction to hold the parts against relative lonaituclinal niovemcnt and to be disengaged upon relative rotation of the parts in the other directio'n to allow such relative longitudinal movement, means on said intei'engageable means positioned for coaction to cause the parts to rotate together in said one direction When said interengageable means are interen' gaged, means on the parts positioned for coaction to cause the parts to rotate together in the other drection When said interengageable means are disengaged, an external longitndinal slot for. red in said inner part and a coil spring in said outer part snrrounding said inner part and having one end sliclably connected to the inner part in said slot, said spring being tixedly connected at its other end to said outer part to apply a force to the parts in all relative longiie the parts said 45. a Weh jar, inner and outer concentrically arran tuhnlar parts rotatahly and lon itndinaily moi/able relative to each other, means on the parts orming impact accs -ositioned tor engageznent to dc'iivcr an in i tct from one to the other of the parts When the oarts reach the limit of their relaive iongitndinal movernent in either direction, intcrengageahle means on the parts positioned for nterengageinent upon relative rotation of the parts one direction when the parts are at the limit of their rclative longitndinal movement in either dircction to hold the parts against relative longitndinal movement and to he disengaged upon relative rotation of the parts in the other directiC-n to allow such relative longitudinal movement, means on said interengagea'ole means positioned for coaction to cause the parts to rotate together in said one direotion when said interengageable means are interengaged, means on the parts positioned for coaction to cause the parts to rotate together in the other direction When said interengageahie means are disengaged and yieidable means positioned for coaction With the parts to yieldingly resis* e rtive rotation of the parts in a direetion to dis- Reterences 'Cited by the Exarniner UNITED STATES PATENTS CHARLES E. GCONNELL, Primary Exaizner. 

1. IN A WELL JAR, INNER AND OUTER CONCENTRICALLY ARRANGED TUBULAR PARTS ROTATABLY AND LONGITUDINALLY MOVABLE RELATIVE TO EACH OTHER, MEANS ON THE PARTS FORMING IMPACT FACES POSITIONED FOR ENGAGEMENT TO DELIVER AN IMPACT FROM ONE TO THE OTHER OF THE PARTS WHEN THE PARTS REACH THE LIMIT OF THEIR RELATIVE LONGITUDINAL MOVEMENT IN EITHER DIRECTION, INTERENGAGEABLE MEANS ON THE PARTS POSITIONED FOR INTERENGAGEMENT UPON RELATIVE ROTATION OF THE PARTS IN ONE DIRECTION WHEN THE PARTS ARE AT THE LIMIT OF THEIR RELATIVE LONGITUDINAL MOVEMENT IN EITHER DIRECTION TO HOLD THE PARTS AGAINST RELATIVE LONGITUDINAL MOVEMENT AND TO BE DISENGAGED UPON RELATIVE ROTATION OF THE PARTS IN THE OTHER DIRECTION TO ALLOW SUCH RELATIVE LONGITUDINAL MOVEMENT, AND MEANS ON THE PARTS POSITIONED FOR COACTION TO PREVENT INTERENGAGEMENT OF SAID INTERENGAGEABLE MEANS WHEN THE PARTS ARE IN POSITIONS BETWEEN THE LIMITS OF THEIR RELATIVE LONGITUDINAL MOVEMENT. 